This invention relates generally to a beverage brewing device which automates many of the steps involved in brewing a beverage.
Automatic coffee brewing devices are known in the art but have not overcome problems associated with automatic brewers. For example, U.S. Pat. No. 4,633,771 to Anderl shows an automatic coffee brewing device which incorporates a movable piston to regulate the coffee brewing cycle. The piston as shown in Anderl is axially moved by a rod which is driven by a motor. The rod advances or retreats based on its engagement with a rotating cam disk. A problem arises with the device of Anderl in that the notches in the cam disc are prone to cause improper brewing if they become coated or clogged with foreign matter. Foreign matter is likely to accumulate on the disc because of the environment in which it operates which includes ground coffee fines and chaff and high humidity due to the coffee-brewing operation.
Another problem with the device as shown in Anderl is that it is difficult to keep the coffee-brewing chamber clean and to exhaust spent coffee grounds. Anderl shows only a single spray head which proves inefficient and unthorough in flushing spent coffee grounds from the brew chamber.
Another automatic brewing device is shown in U.S. Pat. No. 4,694,737 to Wittlinger. The device as shown in Wittlinger is similar in its operation to the device in Anderl but does not provide improvements resolving the problems of Anderl. Rather, the device in Wittlinger shows improvements to the filtering assembly as used in the brew chamber. The filter shown in Wittlinger specifically uses a stainless steel material which is etched to form small diameter micro-perforations therethrough. With reference to FIG. 4, the micro-perforations etched through the stainless steel sheet material increase in diameter from the upper surface of the sheet as measured towards the bottom surface of the sheet. In other words, when viewed cross-sectionally as shown in FIG. 4, the micro-perforations form inverted cone or funnel shapes.
The device as shown in Wittlinger has a problem with the stainless steel sheet material in that the micro-perforations are formed overlying a rigid supporting member therebelow. With further reference to FIG. 4, the generally thin stainless steel sheet lays on top of a substantially thicker supporting member. The supporting member provides structural support to support the weight of the coffee grounds and brewing water saturated therein during a brewing cycle. However, the micro-perforations which are out of register with the large diameter holes formed through the supporting member tend to clog with soluble sediments and other matter due to the inverted funnel shape. Such clogging is prone to unsanitary developments which may affect the taste and the quality of the beverage brewed therein. Further, the top edges of the micro-perforations tend to catch particulate matter when the grounds are exhausted from the brew chamber by a spray of flush water. Thus, the device in Wittlinger retains some particulate matter from the previous brewing cycle.
One alternative to the micro-perforation material shown in Wittlinger is a woven material with extremely fine threads forming extremely fine perforations therebetween. However, the woven pattern, similar to the micro-perforations as shown in Wittlinger, tend to catch particulate matter and harbor sediment and other matter in the intersections between the woven threads. Therefore, woven material does not overcome the problems of the filter material as shown in Wittlinger.
Heretofore, no known device has overcome the problems as discussed hereinabove.